1. Field of the Invention
This invention is directed to weapons and weapon systems employed by ground-based personnel in defense against helicopter assault. The invention is particularly related to a weapons system intended to entangle the rotor systems of an enemy helicopter by means of a cable descending on the rotor system from above.
2. Description of the Prior Art
The Aviation Safety Board has data available on various types of rotor blade impacts with wires. The wires employed in the production of this data were restrained in the manner of high tension lines and the damage was inflicted on the rotor by the stoppage or catastrophic failure of the rotor system. In some cases, extraneous pieces of communications wire have caused helicopter crashes by becoming entangled in the rotor system. It is well recognized that the rotor system of a helicopter is extremely vulnerable for it constitutes not only the propulsion mechanism but also the lift generating mechanism of the aircraft. If the rotor of the helicopter is defeated while the helicopter is airborne at any significant altitude, the likelihood of safe landing on the part of the helicopter is very low.
The prior art does reveal weapon systems intended to defeat aircraft by means of interaction between a cable and a flight system of that aircraft. In particular, U.S. Pat. No. 2,805,622 to Cammin-Christy discloses a rocket missile having a line attached thereto for interaction with a fixed wing aircraft driven by a propeller. Since most modern fixed wing aircraft of military importance no longer employ propeller-driven engines but rather jet engines and since the wing structure of such aircraft typically employs a dramatic rake angle, the utility of the system shown in the Cammin-Christy patent is very limited. Nonetheless, the basic concept of downing aircraft by interaction with a length of cable is well known in the prior art and the means for deploying the cable other than rocket missiles are known. For example, barrage balloons and the like were employed extensively in the 1930s and 1940s and during the Battle of Britain, bomber crews sometimes threw cables at attaching fighter planes.
In the last six to eight years, dramatic developments in the use of helicopters as assault vehicles and fire support platforms have occurred.Further development of helicopter systems is an integral part of conventional armed force structure as expected. One of the major considerations of any ground-based forces defending against a helicopter-based invasion, is identifying the absolute minimum force necessary to defend against an enemy that has the advantage of numerical superiority as well as ability provided by the helicopter. In that context, it was intended that the present weapons system be one which can be very simply employed by ground troops and that it comprise essentially a minimum adjunct to already existing weapons systems. It was further intended that the present weapons system be usable in the vicinity of friendly troops with little or no hazard to those troops due to accidental overshoot, misfire, or the like.
The problem of close proximity of friendly troops is particularly relevant where the intended site of any helicopter assault operation is specific targets in the rear of a main resistance area such as command and control centers, logistical installations, air defense sites, and bridge heads which an enemy force might wish to secure to the rear of a main defense line so as to ensure a high momentum to any overall assault plan. The rear area target might be only lightly defended in view of its distance from the main line of assault but still might contain a significant population of friendly troops which would prevent the employment of a large amount of incoming firepower. It is further desired that the weapons system be employable against helicopters while at a moderate altitude over a landing zone.